There is a growing need, in the field of computer graphics, and simulation involving the same, to render a skinned visual mesh to achieve smooth deformation of deformable objects, such as a piece of dough. Shape matching is a popular method for simulating deformable objects in real time as it is fast and stable at large time steps. Although shape matching can simulate large elastic deformation and ductile fracturing, these techniques are limited to situations with relatively small plastic deformation.
Some existing skinning techniques use shape matching for clusters of particles having orientation information. The visual mesh is then skinned to either the clusters or the particles. When skinning to the clusters using shape matching techniques, the orientation information is utilized, and the visual vertex is not required to be within a convex hull of the cluster's centers. However, a very large number of clusters are required for this skinning method to achieve smooth deformation because the clusters are typically spaced far apart.
Alternatively, some skinning techniques skin to the particles, where only a relatively small number of particles are required when the particles are densely sampled. However, this method requires that the visual vertex be within the convex hull of the particles to prevent the appearance of extrapolation artifacts. Further, rotation information may not be reproduced if displacement is interpolated.
What is needed is a technique for skinning a cluster based computer simulation with a visual mesh that combines the advantages of skinning to particles and skinning to clusters, maintains rotation information, and does not require the visual mesh vertex to be within the convex hull of particles.